What would be the average luminosity of the accretion disk, if it continuously radiated that energy over a period of 12 billion years?

The average luminosity can be calculated as E/delta t , where E is the total amount of energy radiated by the accretion disk: E=mc^2. m is the mass of the accretion disk, c is the the speed of light. Delta t is known from the question delta t = 12 billion years. Unknown is the mass of the accretion disk and this mass depends on the type of the accretion disk.

energy stored in the capacitor= 9.72 x 10⁻⁴ j

explanation:

the energy stored in the capacitor is given by

e= 1/2 c v²

e= energy stored

c= capacitance= 1.5 µc= 1.5 x 10⁻⁶f

v= potential difference=36 v

so energy stored= e= 1/2 (1.5 x 10⁻⁶) (36)²

energy stored= 9.72 x 10⁻⁴j